If you haven’t already check out the CPA offers for mobile phones
Pros: High CPA for simple submits etc.
Cons: Advertisements are phone type or carrier specific, this makes you have to be very careful in ppc campaigns. Luck, Google now targets iPhones and Androids.

Check out Offermobi first.

Here is a snapshot of what type of a CPA offers ore inside. This CPA company is easy to apply and get accepted it, but be sure to read the conditions.

Mobpartner is much like Offermobi. Almost the same really. The majority of both of the CPA submits are regarding dating.
Dating is hot - So are smartphones.
All of these people are looking for other people using a smart phone, maybe even device specific. This is a demographic of people who cannot be ignored.